An organic EL device using electroluminescence (hereinafter called EL) of an organic material comprises an electron-transport layer and an organic light-emitting layer between an anode electrode and a cathode, electrode, and is well known as a light-emitting element capable of low voltage drive and high-luminescence light emission.
For this reason, attention has been recently focused on display devices using organic EL devices, such as TV, smartphones, tablet terminals, and personal computers.
In the display device, for example, the inside of the display area defined by a wall (bank) is coated with ink containing an organic light-emitting material, organic light-emitting layer is formed by drying the coated ink, and the organic EL device is manufactured.
If the coated ink is merely dried, however, the organic light-emitting layer at a central portion of the display area is dried with ink existing in the surrounding but the organic light-emitting layer at a peripheral portion of the display area is dried with no ink existing in the surrounding. For this reason, non-uniformity in drying occurs at the organic light-emitting layer at the central portion and the organic light-emitting layer at the peripheral portion, in the display area. For this reason, the light emission property of the organic light-emitting layer may become non-uniform due to the non-uniformity in drying. In this case, the peripheral area different in light emission property from the central portion may be regarded as a dummy area which is not a valid display area. For increase in productivity, the valid display area is required to be larger as compared with the size of the entire body of the substrate.
The embodiments provide a display device capable of making the valid display area larger as compared with the size of the entire body.